feat: make hook redirect IP configurable from launcher

The DLL now reads openfut.cfg from its own directory on DLL_PROCESS_ATTACH
and uses the IP it contains as the redirect target instead of hardcoding
127.0.0.1. Falls back to 127.0.0.1 if the file is absent.

The launcher writes openfut.cfg alongside version.dll when deploying, and
the Setup tab exposes a "Redirect IP" field with an "Update" button that
rewrites openfut.cfg in-place without redeploying the DLL. Useful when
running the emulator on a different machine on the LAN.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/setup.rs

@@ -68,10 +68,11 @@ fn run_elevated(script: &str) -> anyhow::Result<()> {
 
 // ── DLL hook deployment ───────────────────────────────────────────────────────
 
-/// Deploy openfut_hook.dll into the FIFA 23 game directory.
-/// Uses a name that FIFA 23 loads but doesn't need from system: `version.dll`.
-/// Proton will prefer the local copy over the system one.
-pub fn deploy_hook_dll(dll_src: &Path, game_dir: &Path) -> anyhow::Result<()> {
+/// Deploy openfut_hook.dll into the FIFA 23 game directory and write
+/// openfut.cfg with the redirect IP the hook will use.
+/// Uses `version.dll` as the hijack name — FIFA 23 loads it but defers to
+/// the system copy, so Proton picks up our local one first.
+pub fn deploy_hook_dll(dll_src: &Path, game_dir: &Path, redirect_ip: &str) -> anyhow::Result<()> {
     if !dll_src.exists() {
         anyhow::bail!(
             "Hook DLL not found at {}. Build it first with:\n\
@@ -81,8 +82,18 @@ pub fn deploy_hook_dll(dll_src: &Path, game_dir: &Path) -> anyhow::Result<()> {
         );
     }
     std::fs::create_dir_all(game_dir)?;
-    let dest = game_dir.join("version.dll");
-    std::fs::copy(dll_src, &dest)?;
+    std::fs::copy(dll_src, game_dir.join("version.dll"))?;
+    std::fs::write(game_dir.join("openfut.cfg"), redirect_ip)?;
+    Ok(())
+}
+
+/// Update only openfut.cfg without redeploying the DLL.
+pub fn update_hook_config(game_dir: &Path, redirect_ip: &str) -> anyhow::Result<()> {
+    let cfg = game_dir.join("openfut.cfg");
+    if !cfg.exists() {
+        anyhow::bail!("Hook DLL not deployed yet — deploy first.");
+    }
+    std::fs::write(cfg, redirect_ip)?;
     Ok(())
 }